Air conditioning apparatus



Dec. 7; 1943. c 2,336,056

AIR CONDITIONING APPARATUS Fi'led May 28, 1941 2 Sheets-Sheet .1

F. CAIN 2,336,066

AIR CONDITIONING APPARATUS Filed llay 28, 1941 2 Sheets-Sheet 2 Dec. 7,1943.

Patented Dec. 7, 1943 UNITED STATES PATENT OFFICE 2,336,066 AIRCONDITIONINGAPPARATUS FrankCain, Park Ridge, 111. Application" May 28,1941, Serial Nm 395,677

12 Claims. (01;:62-1351) The present invention relates generally toapparatus for conditioning or cooling air. More particularly theinvention relates to that type of air conditioning apparatus which isdesigned for use in a room for human occupancy and as its main partscomprises a box-like supporting structure, a cooling tank on thestructure and with a column of water therein, a'radiator-like heatexchanger also on the supporting structure, a pipe system forcirculating cool water from the tank through the-heat exchanger and thenback to the tank in order to cool the exchanger, and a motor driven 'fanopposite the heat exchanger for-so flowing the air in the room that itpasses repeatedly through the heat exchanger and hence is cooled as aresult of the absorption of heat by "the exchanger.

One object of the invention is to provide an air'conditioning apparatusof this type which is generally an improvementupon, and has certainadvantages over, previously designed apparatus for the same purpose andnot only efiiciently and effectively fulfills its intended purpose butalso is in the form of a self-contained unit.

Another object of the invention is to provide an apparatus of the typeunder considerationin which the various operating parts, such as thetank,heat exchanger and the fan, are compactly arranged withrespectto-the supporting structure and the supporting structure isshaped and designed to serve as a housing for such parts and includes anopen ended duct which encompasses or surrounds the heat exchanger andfan andis adapted to have the air in the room circulate therethroughduring drive or operation of the fan.

Another object of the invention is to provide an airconditioningrapparatus of the aforementioned type which includes asanother main part thereof a mechanical refrigerator unit of thecompressor-condenser-receiver-evaporator type for cooling the'tank.

Anotherobject of the invention is to provide an apparatus of the lastmentioned character in which the refrigerator unit is mounted on thehousing forming supporting structure beneath the tank, and hasthe-evaporator thereof'disposed in the column of water in the tank sothat "it is adapted when the unit is in operation and'the fan isinoperative to form part ofthe'water in the tank into ice so that thelatter is available for tank cooling purposes when the ian'is again setinto operation during useof the apparatus 'for aircooling purposes.

Another object of the invention is to provide an =-airconditioningapparatusof the typeand character-last mentioned which in addition tothe mechanical refrigerator unit, includes means for flowing cool waterfrom a' tap orother independent source of supply throu h the exchangerwhen the pipe system between the exchanger and the tank is closedagainst the circulation of Water theret'hrough.

Still another'object of the invention is to provide an airconditioning-or cooling apparatus of the type heretofore specified whichis so designed that the-mechanical refrigerator-may be operated oridriven continuously; that is, twenty-four hours per-day, and hence-t-he*user-or owner may benefit from low current rates which-'arebasedupon continuous current consumption as distinguished from intermittentconsumption.

A further-object oft-he'invention is-to provide an'airconditioningapparatus of the typeand character here-under-con-sideration whichincludes as parts thereof: (1) a novel form ofmoisture eliminator "in the discharge end of the open ended duct whichsurrounds the heat exchangerrand fan; (2) novel neans for cooling by tapwater the condenser of the "mechanical refrigerator unit; and (3)improved. control means for the mechanicalrefri erator. I

"A still .further object of the invention is to provide an airconditioning apparatus which isgenerally (of new design and maybemanufactured as .wellasoper'ated andgmaint'ained ata ,comparativelylowcost.

Other. objects of .the invention and the various advantages "andcharacteristics of the present'a'ir conditioning apparatus. will beapparent from a consideration ofthe following detailed description.

The invention'consists in the severalrnovelifeatures which arehereinafter setiorthandare more particularly defined .byiclaims at theconclusion hereof.

In the drawings which accompany. and form a part of .i thisspecification or "disclosure and-sin which like numerals .of referenceidenote corresponding parts throughout the several yiews:

- Figure 7 1: is a vertical long tudinal section of an air conditioningapparatuaembodying :;the invention;

Figure .12 is :another" vertical'along-itudinal t:sectional: view :of'theapparatus jtaken however on a zlineiior plane which :is laterallyo'fisetwwith irespect :to the :line ::ror.-.p1anef:on which the .sectionconstituting 'l igure -1 is taken;

Figures 3 and 4 r are horizontal .seotions :taken respectively on lines'-3- 3--and 4- -4 -of "it igure: 1; and

Figure 5 is a side view of the control handle of one of the valves ofthe apparatus.

The apparatus which is shown in the drawings constitutes the preferredembodiment of the invention. It is essentially a self-contained unit andis primarily designed or adapted to condition or cool the air in a roomfor human occupancy, in order to afiord comfort against excessive oroppressive heat. As parts thereof the apparatus comprises a supportingstructure It, a cooling tank H; a heat exchanger l2 and a fan IS.

The supporting structure It) is of box-like design and serves as ahousing for the various operating parts of the apparatus.

paratus is employed and consists of a bottom forming base M, a pair ofside walls l5 and a pair of end walls to and ii. The side walls I5 restupon and project upwardly from the side margins of the base it. and aredisposed in parallel relation. The end walls lfiand II rest upon andproject upwardly from the end margins of the base and extend between andserve laterally to space the side walls 15.

The tank H is located in the upper portion of the supporting structureill, as shown in Figures 1 and 2. It is designed to hold a column ofwater and embodies a bottom it and a pair of ends 19 and so. The bottomi8 is positioned substantially midway between the top and bottom of thesupporting structure Ii] and overlies one end of, and extends inparallel relation with, the base M of the supporting structure. Itextends between and is suitably secured to the side walls I5 of thesupporting structure and preferably is formed of plate metal. The end IQof the tank extends upwardly from one end of the bottom l8 and is spacedinwardly a comparatively small distance from the upper portion of theend wall it. Its length corresponds to the width of the bottom 18 andits end margins are secured to the adjacent portions of the side wallsiii of the supporting structure. The end 26 of the tank H is spacedinwardly from the end wall I? of the supporting structure and is securedat the end margins thereof to the adjacent portions of the side walls 5.The inner faces of the ends is and 28), the upper face of the bottom Itand the portions of the side walls which extend between the ends l9 andand are above the bottom i8, define the interior of the tank H. The topof the tank is normally closed by a cover 2| which is preferably ofhollow design and filled with insulating material and has its endmargins resting loosely upon the upper margins of the end wall It of thesupporting structure it! and the end of the tank H.

When it is desired to have access to the interior of the tank ll it isonly necessary to remove the cover 2!. The end 2!] of the tank, the endwall l6 of the supporting structure, and the portion of the side wallsof the supporting structure which form the sides of the tank H are ofhollow design and filled with insulating material, as shown in thedrawings, so that the tank interior is insulated from the atmospheresurrounding the apparatus. The bottom l8 and the end l9 of the tank IIare surrounded by an L- shaped jacket 22. This jacket is normally filledwith water and consists of a vertical leg 23 and a horizontal leg 24.The vertical leg is formed between the end I9 of the tank H and theupper portion of the end wall l6 of the supporting structure Ill andreceives water from It is adapted to rest upon the floor of the room inwhich the 3113-,

the tank interior by way of a horizontal series of laterally spacedholes 25 in the upper margin of said end 19. The horizontal leg 24 ofthe jacket is formed between the bottom E8 of the tank and ahorizontally extending wall 26. The wall 26 is secured to the adjacentportions of the sides 15 of the supporting structure and has one endthereof secured to the lower end of the tank end 28 and its other endsecured to the central or intermediate portion of the end wall [6 of thesupporting structure. When the Water in the tank H rises above thebottom portions of the holes 25 in the upper margin of the tank end IEit flows or spills into the vertical leg 23 of the jacket 22 and thenflows downwards into the horizontal jacket leg 24. Two laterally spacedbaffles 21 (see Figure 3) are disposed in and extend longitudinally ofthe horizontal leg 24 of the jacket and are so arranged that the waterin flowing through such leg travels in a serpentine or sinuous course. Ablock 28 of cork or other material is located in the lower end of thevertical leg 23 of the jacket and forms at one end thereof a restrictedpassage between said lower end of the vertical leg and the inlet or.water receiving end of the horizontal leg 24.

The heat exchanger i2 is located beneath the inner end of the tank II.It is of radiator-like design, and consists of an upper header 30, alower header 3! and a series of tubes 32 between the two headers. Theupper header 30 is secured in any suitable manner to the inner end ofthe wall 26. The lower header 3! communicates with the upper header byway of the tubes 32 and is disposed over one end of the base 14 of thesupport ing structure HE. A pipe 33 (see Figure 1) extends between thelower header 3! of the heat exchanger and the discharge end of thehorizontal leg 24 of the jacket 22 and permits any water in the waterjacket to flow downwardly into the lower header SI for up-flow throughthe tubes 32 and into the upper header 3%. The upper header 3G isconnected by a pipe 35 to the housing inlet of a pump 35, which, asshown in Figures 1 and 4, is located beneath thewall 26 and is supportedon a bracket 35 on the inner face of the end wall 16 of the supportingstructure ND. The pipe 34 extends substantially horizontally .andunderlies the wall !6. The pump 35 is connected for drive by an electricmotor 31 and has a discharge pipe 38 leading from the outlet of itshousing. This pipe 38 consists of a vertically extending section 89 anda horizontally extending section it. The section 39 projects through'ahole in the wall 26 and leads upwardly. through the vertical leg 23 ofthe water jacket 22. The horizontally extending section 40 of the pipe38 overlies the bottom E8 of the tank and is disposed directly beneaththe cover 2! when'the latter is in its closed or normal position. It ispositioned above the column of water in the tank Hand has one endthereof connected to the upper end of the vertically extending section39. The other end of the section 40 supports, in a depending manner, andis in communication with, a plurality of depending discharge tubes 4|.These tubes-terminate above the tank bottom IB and have discharge holes42. When the pump 35 is in operation water flows from the jacket 22downwardly through the pipe 33 into the lower header 3| of the' heatexchanger I2, then flows upwards through the tubes 32 into the upperheader 3G and thence to the pump 35 via the horizontally extending pipe34. From the pump the pumped water flows through the pipe 38.- andthence into the tank II by way of the discharge tubes 4 I. From the tankI I the water flows back into the jacket 22 through the holes 25 in theupper margin of the tank end I9. When the level of the water in the tankis above the bottom of the holes 25 and the jacket 22 is filled with'water, drive ofthe pump operates to cause the water to circulate fromthe jacket to and through the radiator and thence into the tank and backto the jacket. The motor 37 for driving the pump is controlled by afloat controlled switch 43 in the upper end of the vertical leg 23 ofthe jacket 22. When the float for controlling the switch is in anelevated position due to the leg 23 of the jacket 22 being filled withwater, the switch 43 is held in its closed position with the result thatthe pump 35 operates, as hereinbefore described, to effect circulationof cool water from the tank I I to and through the heat exchanger I2.When the float drops in connection with hereinafter described drainageof water from the jacket 22 it serves to open the switch and thus stopsdrive of the pump 35 by the motor 37.

The fan I3 is positioned between the heat exchanger I2 and a verticallyextending partition 44. It is driven by means of an electric motor 45.The partition extends between the inner end of the bottom forming baseI4 of the supporting structure It] and the horizontally extending wall26 and defines with said base and the lower portions of the side wallsI5 and the end wall I6 a compartment 56. The motor 45 is mounted on abracket 4'! on the partition 44 and is controlled by a switch (notshown). 48 extends between the lower header 3i of the heat exchanger I2and the upper portion of the end wall ll of the supporting structure ii]and forms a substantially U-shaped air circulating duct 49. An opening59 in the lower portion of the end wall I? constitutes the inlet end ofthis duct and a grill equipped opening 5! between the upper end of thetank end 20 and the upper portion of the end wall I1 constitutes theduct outlet. The fan I3 is so designed that when it is driven by theelectric motor 45 it operates to draw air into the duct through the hole50 from the space around the apparatus and then to force the air throughthe heat exchanger I2 and out of the duct via the opening 5|. When coolwater is being circulated through the heat exchanger and the fan is inoperation the air which flows through the duct is cooled as it comes incontact with the heat exchanger.

In addition to the supporting structure Ill, cooling tank I I, heatexchanger l2 and fan I3 the apparatus comprises or includes as a partthereof a mechanical refrigerator unit 52. This unit is disposed for themain part in the compartment 46 beneath the cooling tank and operates ashereinafter described to chill the water in the tank when the pump 35 isin operation and to freeze the water in the tank when the pump isinoperative. It is designed and intended to operate constantly andconsists of a compressor 53, a condenser 54, a receiver 55, anevaporator 53, a high pressure refrigerant line 51 and a low pressurerefrigerant line 58. The high pressure refrigerant line leads from thecompressor to the evaporator and includes the condenser 54 and thereceiver 55. The low pressure refrigerant line constitutes a refrigerantreturn and leads from the evaporator to the suction side of thecompressor. The compressor is of the air cooledvariety and is positionedin the compartment 46. It rests on- An inclined partition I the base I4and is driven by an electric motor 59 by way of a belt and pulleyconnection 6%). When the compressor is in operation it operates, as wellunderstood in the art, to compress the refrigerant prior to passage ofthe latter to the evaporator; The condenser 54 of the unit is located inthe compartment 46 in close proximity to the compressor and serves tocondense the compressed refrigerant. The receiver '55 is also located inthe compartment 46. It is connected to the high pressure refrigerantline 5? at a point between the condenser and the evaporator and servesas a storage tank for the refrigerant after the latter is condensed orliquified by the condenser. The evaporator 56 consists of a plurality ofserially connected coils 6I in the tank II and is connect ed to thedischarge end of the high pressure re frigerant line 57 by way of anexpansion valve 62. The latter is controlled by a thermo bulb 63 in thecompartment 48. The bulb 63 is located at the discharge or outlet end ofthe low pressure refrigerant line 53 in the immediate proximity of theinlet part of the compressor. By 50 locating the bulb the mechanicalrefrigerating unit 52 is so controlled that it is adapted for twentyfo'ur hour a day operation. If the bulb were located in the cooling tankit would not properly control the expansion valve for full timeoperation of the unit. By locating the bulb as shown there is no slackin the low pressure line and the spent refr'igerant enters thecompressor at a low temperature and assists in cooling the compressor.The coils SI of the evaporator correspond in num her to the dischargetubes M and are associated with said tubes respectively. They aresubstantially fully immersed in the column of water in the tank I I andserve, when the refrigerator unit is in operation, either to chill orfreeze the water in the tank. The low pressure refrigerant line 58extends between and connects the outlet end of the evaporator and thesuction side of the coinpressor. When the unit is in operation therefrigerant is drawn into, and compressed by, the compressor and thenflows through the condenser and the receiver and to the expansion valve62 via the high pressure refrigerant line 57. When the refrigerantpasses through the expansion valve into the evaporator it expands andthus reduces the temperature of the evaporator. After passing throughthe evaporator the spent refrigerant returns to the compressor by way ofthe low pressure refrigerant line 58. When the water is being circulatedthrough the tank, the water jacket and the heat exchanger, as the resultof operation of the pump 35, chilling of the water takes place due tothe action of the evaporator and as a result the air which is circulatedpast the heat exchanger by the motor driven fan I 3 is reduced intemperature. When the water in the tank is stagnant due to stoppage ofthe pump 35 it freezes due to the chilling or refrigerating effect ofthe evaporator.

It is contemplated that during the warm or hot period of the day thepump 35 will be in operation and that during the cool parts of the dayor at night when no air cooling or conditioning is necessary the pumpshall not be in operation. When the pump is not in operation, asheretofore pointed out, there is no circulation of water through thetank and the water in the tank turns into ice as the result of theaction of the evaporatorfifi of the mechanical refrigerator unit 52.When the pump is started after the formation of ice in the tank II waterin the jacket 22 is drawn through the heat exchanger and is then-forcedunder pressure into the tank ll through the tubes 4|. The pumped wateris chilled or cooled as a result of contact with the ice in the tank andthen flows back into the vertical leg 23 of the jacket through the holes25 in the upper margin of the tank end 19.

For the purpose of draining the jacket 22 and thus preventing thefreezing of water therein when the mechanical refrigerator unit 52 isop-' erated to form the water in the tank Ii into ice drain means 64 isprovided. This means consists of a drain pipe 65, a drain tank 66 and adrain pipe 61. The tank 66 is suitably supported in the compartment 46adjacent the upper end of the partition 44. It is open at the topthereof as hereinafter described and carries at all times during normaloperation of the apparatus, a column of water. The drain pipe 65 leadsfrom the upper header 36 of the heat exchanger l2 to the tank 66, asshown in Figure 2, and in cludes a valve 68. It has a comparativelylarge diameter and is positioned beneath the horizontally extending wall26. The valve 66 is of any suitable type or character and embodies acontrol handle 69 adjacent one of the side walls l5 of the supportingstructure Hi. When it is desired to drain the jacket 22 the valve 68 isopened by proper manipulation of the control handle 69. As soon as thevalve is opened the water in the jacket 22 drains into the drain tank 66by way of the heat exchanger l2 and the drain pipe 65. The drain pipe 61is of L-shaped construction and consists of a vertically extending pipesection 16 and a horizontally extending pipe section. The section 16(see Figure 2) extends through the bottom of the drain tank 66 and is ofsuch length that the upper end thereof terminates slightly beneath thetop of the tank 66. The horizontal section H of the drain pipe 67underlies the bottom forming base M of the supporting structure it) andleads from the lower end of the section 76 to a waste pipe or sewer (notshown). When the valve 63 is in its open position the water which flowsthrough the drain pipe 65 from the jacket flows into the tank 66 andthen after rising to the top of thelatter passes from the apparatus viathe drain pipe 61.

A column of water is maintained in the tank 66 of the discharge means 64by way of a supply or make-up water tank 12. This tank, as shown inFigures 1 and 2, is located in the upper or discharge end of the aircirculating duct 49. It is suspended from a top plate 13 at the upperend of the end wall l! of the supporting structure and supplied withwater by way of a pipe 14. The latter leads from a tap or other watersupply and is provided with a float controlled valve 15 at its dischargeend. The float for the valve 15 is so arranged that it closes the valvewhen the level of the column of water in the tank 12 is the same as thelevel of the water in the tank Ii and opens the valve when the waterdrops below such level. As a result of the action of the float the waterin the tank 12 is always at a constant level. A pipe 16 (see Figure 2)leads from the bottom of the supply tank l2 to the drain tank 66. Thedischarge end of the pipe 76 terminates within the tank 66 and isprovided with a float controlled valve H. The float for the lastmentioned valve so controls such valve that a column of water ofconstant height is maintained in the tank 66. The tank 66 serves notonly as a part of the drainage means 64 for the jacket 22 but also as amedium for constantly supplying water to a jacket 18 around thecondenser 54 of the mechanical "refrigerator unit 52. The jacket18'completely surrounds the condenser." A pipe 19 leads from thebottomof the tank 66 to the top of the jacket 18 and a drain pipe leadsfrom the bottom of the jacket to the horizontal section H of the drainpipe 61. When the apparatus is in operation water from the tank 66 flowsconstantly through the jacket 18 and assists in condensing thecompressed refrigerant in the condenser. A normally open water supplypipe 8| extends between the bottom of the supply tank 12 and the lowerheader 3| of the heat exchanger l2. This pipe serves to supply the heatexchanger with cool tap water for air cooling purposes when the valve 68is open and there is no water in the jacket 22 and operates when thevalve 66 is closed to fill said jacket 22'with water from the tank 12. Avalve 82 is connected to the upper end of the pipe 8| and serves toregulate the flow of water through the pipe to the heat exchanger. Toprevent the pipe 8! from becoming air bound a vent pipe 83 is attachedto the pipe 8| at a point beneath the valve 82. This pipe 83 extendsupwardly alongside of the tank I2 and is of such length that the upperend thereof is positioned above the level of the column of water in thetank 12. An overflow pipe 84 leads from the top of the tank 12 to thevertically extending section 10 of the drain pipe 61 and serves toprevent the tank 12 from overflowing in the event that the float for thevalve 15 should become inoperative or the valve should stick or freezein its open position. The tank T2 is provided on the exterior thereofwith protuberances or bafiles 85 and these, together with the tank,serves as a medium for eliminating moisture in the cooled air which isdischarged from the apparatus via the discharge opening 5| at the upperend of the duct 49. Any moisture which is collected is eliminated by theprotuberances and the tank and drains down the inclined partition 48into a trough 86 beneath the heat exchanger and is discharged fro-m saidtrough into the drain pipe 61 by way of a drain tube 81. To preventexcessive building up of water in the tank II and the jacket 22 anoverflow pipe 88 is provided. This pipe is L-shaped and extends from thetop of the vertical leg 23 of the jacket 22 to the drain pipe 65 of thedrain means 64. The lower part of the pipe 88 has a U-shaped loop in itas shown in Figure 2, so as to form an air trap or lock whereby air isprecluded from flowing from the compartment 46 into the cooling tank I Ishould there be no water in the drain tank 66. Whereas the upper leg orpart of the pipe 88 has been described or shown as being located in thevertical leg of the jacket 22 it is to be understood that it may beotherwise placed or positioned. For example, it may be disposed in thecooling tank II at a point in close proximity to the end '26 of thetank. The pipe 65 is of much larger diameter than the supply pipe 8| inorder that when the valve 68 is opened there is complete drainage ofwater from the jacket even though tap water is permitted to flow throughthe heat exchanger [2 from the tank 12.

When it is desired to set the apparatus in operation the valve 68 isfirst closed and then tap water is permitted to flow into the tank 12via the pipe 14. A portion of' the water which is introduced into thetank 12 flows through the piper BI into the heat exchanger 12 and fromthe latter into the jacket 22 and cooling tank I I. Water also flowsfrom the tank 12 through the pipe 16 into the drain tank 66. When thecolumn of water in the drain tank approaches the top of the tank thefloat controlled valve 11 closes and there is no further flow of waterfrom the tank 12 into the drain tank 66. Water will continue to flowinto the tank 12 until the heat exchanger 12, the jacket 22 and the tankH are filled. At such time the column of water in the tank 12 will havea level equal to that of the level of the water in the tank and jacket,and the valve 15 will close. After filling of the tank I l themechanical refrigerator unit 52 is set in operation; It operates ashereinbefore described to chill or cool the Water in the tank. When itis desired to cool the air in the space surrounding the apparatus theelectric motors for the fan [3 and the pump 35 are started. As soon asthese motors become operative cooled or chilled water is caused tocirculate from the cooling tank H through the jacket 22 and the heatexchanger l2 and then back to the tank. In response to drive of the fanlit by the electric motor 45 air is caused to circulate through the duct45. As the air passes the heat exchanger I2 it is cooled. Because of theoperation of the fan there is a constant circulation of air within thespace around the apparatus and a cooling effect is obtained by theaction of the heat exchanger. In normal operation of the apparatus waterflows from the drain tank 66 through the jacket 18 around the condenser54 and cools the condenser. When it is desired to freeze the water inthe tank H and eifect cooling of the heat exchanger by the flow of tapwater therethrough the valve 68 is opened by proper manipulation of thehandle '69 and the motor for driving the pump 35 is stopped. Immediatelyupon opening of the valve the water in the jacket 22 drains into thedrain tank 66 and is discharged from the latter by way i of the drainpipe 61. As soon as the jacket is empty the water in the tank H becomesstagnant or inert. It freezes and forms into a substantially solid cakearound the coils 6| which constitute the evaporator 56 of therefrigerating unit 52. While ice is being formed in the tank 1 I: thereis a continuous flow of tap water from the tank 12 to and through theheat exchanger 12' and this serves to cool the exchanger so that aircooling is obtained in connection with drive of thefan l3. As soon asthe water in the tank it becomes frozen and it' is desired to use theice for cooling the heat exchanger the valve 68 is closed and thereafterthe pump 35 is set in motion. As soon as the valve 58 is closed waterfrom the tank 12 flows into and fills the jacket 22.. 'As soon as thejacket is filled with water there is no further flow of water from thetank 12: into the heat exchanger 62. As soon as the pump 35- starts tooperate water is drawn from the heat exchanger and forced under pressureinto the tank it via the holes in the tubes M. This water, as heretoforedescribed, comes in contact with the ice and after being chilled there'-by flows back into the jacket 22 and is recirculated through the heatexchanger. It is contemplated, as hereinbefore pointed out, that themechanical refrigerator unit be constantly operated and that the pumpshall only be operated during extremely oppressive heat, such forexample, as those temperatures which are encountered during the Warmpart of the day. It is. further contemplated that at night when coolertemperatures are encountered the valve 68 be opened and the pump 35stopped so as to form ice in the tank II. By such operation there isample cooling of the heat exchanger during the warm part of the day andthe ice in the tank augments the cooling action of the unit. When ice isbeing formed in the tank ll cooling of the heat exchanger [2 takes placeas the result of flow of tap water through the exchanger, as heretoforepointed out. Should it be desired during the formation of ice in thetank to eliminate the flow of tap water through the heat eX- changer itis only necessary to close the valve 82 in the supply pipe 8|. When suchvalve is closed there is no flow of water from the tank 12 through theheat exchanger. Whenever the fan I3 is in operation there is acontinuous flow of air through the duct 49 and past the heat exchanger.Because the apparatus includes the float controlled switch 43 for thepump driving motor 3'! the pump is automatically stopped when the jacket22 is drained as a result of opening of the Valve 68 and isautomatically set in operation when the jacket is filled with make-upwater from the tap as the result of closing of said valve 68. i

The herein described air conditioning apparatus efliciently andeffectively fufills its intended purpose and may be operatedeconomically, especially in territories where low current rates prevailin connection with continuous current consumption. It is essentially aselfcontained unit and comprehends a compact arrangement of itscomponent parts.

The invention is not to be understood to be restricted to the detailsset forth since these may be modified within the scope of the appendedclaims without departing from the spirit and scope of the invention.

Having thus described the invention what I claim as new and desire tosecure by Letters Patent is:

1. In an air conditioning appartus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means for refrigerating the water therein, a hollow heatexchanger adapted to have air circulated past it, a system forcirculating water from the tank through the heat exchanger and thenceback to the tank, including a motor drivenpump and a water jacketcommunicating with the topof the tank and adapted to have Water flowfrom the tank into and through it, means for draining the jacket of anywater therein, and means for automatically stopping the pump upondrainage of the jacket.

2. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means associated therewith for refrigerating the water in it; ahollow heat exchanger positioned beneath the tank and adapted to haveair circulated past it; a system for circulating water from the tankthrough the heat exchanger and thence back to the tank comprising ajacket extending between and communieating with the heat exchanger andthe top of the tank and adapted during use of the system to have waterspill directly into it from the tank and deliver the water to the heatexchanger, a return pipe leading from said heat exchanger and havingthedischarge end thereof arranged to discharge into the tank, and amotor driven pump in said pipe; valve controlled means for draining the.jacket of any water therein when the system is not in use; and valvecontrolled means for filling the jacket with water from an outsidesource whenit is desired to render the 'system operative.

'culated past. it; a systemfor circulating water from the tank throughthe heat exchanger and thence back to the tank comprising a jacketbetween and communicating with the heat exchanger and the top of thetank, a return pipe leading from the heat exchanger and having thedischarge end thereof arranged to discharge into the tank, and a motordriven pump in said pipe, means for draining the jacket of any watertherein when the system is not in use; and means for automaticallystopping the pump upon drainage of the jacket.

7 4. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water, amechanical refrigerator unit having evaporator coils disposed in thetank for chilling or freezing the water therein, a hollow heatexchanger, and a system for circulating water from the tank through theheat exchanger and back to the tank, normally filled with water andcomprising a jacket extending between and communicating with the heatexchanger and the top of the tank, a return pipe leading from the heatexchanger 'and having the discharge end thereof overlying the tank andprovided with depending apertured tubes adjacent the evaporator coils,and a motor driven pump in the return pipe.

5. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water, 'amechanical refrigerator unit having evaporator coils disposed in thetank for chilling or freezing the water therein, a hollow heatexchanger, a system for circulating water from the tank through the heatexchanger and back to the tank, normally filled with water andcomprising a jacket extending between and communicating with the heatexchanger and the top of the tank, a return pipe leading from the heatexchanger and having the discharge end thereof overlying the tank andprovided with depending apertured tubes adjacent the evaporator coils,and a motor driven pump in the return pipe, and means for draining thejacket of any water therein and thus rendering the system inoperative.6. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means associated therewith for cooling the water in it, a hollowheat exchanger adapted to have air circulated past it, controlla- 'blemeans for circulating water from the tank through the'heat exchanger andback to the tank, a water supply tank having means for continuouslymaintaining a column of tap water therein, and means for circulating tapwater from the sup ly tank through the heat exchangerwhen saidcontrollablecirculating means is inoperative. I

7. In an air conditioning apparatus of the character described, thecombination of a refrigerating tank ada ted to contain a column of waterand having associated therewith means for cooling the water in it.- ahollow heat exchanger disposed beneath the tank and adapted to have aircirculated past it, means for circulating wa ter from the tank throughthe heat exchanger and back to the tank including a hollow elementleading from the top of the tank to the heat exchanger and adaptedduring use of the circulating means to have water spill directly into itfrom the tank and to deliver the water by gravity to the heat exchanger,a valve controlled drain pipe for draining the hollow element when thecirculating means is not in use, a make-up water tank above the heatexchanger, and a pipe between, and serving to connect, said make-upwater tank and the heat exchanger.

8. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means for refrigerating the water therein, a hollow heatexchanger disposed be-v neath the tank and adapted to have aircirculated past it, means for circulating water from the tank throughthe heat exchanger and then back to the tank, including a jacketextending between and communicating with the heat exchanger and the topof the tank and adapted during use of the circulating means to havewater spill directly into it from the tank and deliver the water bygravity to the heat exchanger, a valve controlled drain pipe fordraining the jacket of any water therein when the circulating means isnot in use, a make-up water tank above said heat exchanger, and a valvecontrolled pipe extending between, and serving to connect, the make-upwater tank and the heat exchanger.

9. In an air conditioning appartus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means for cooling the water in it, a hollow heat exchangerdisposed beneath the tank and adapted to have air circulate past it,means for circulating water from the tank through the heat exchanger andback to the tank, a valve controlled drain pipe adapted when the valvethereof is opened to drain water from the circulating means and renderthe latter inoperative, a water supply tank disposed adjacent thecooling tank and above the heat exchanger and having means associatedtherewith for continuously maintaining it full of tap water, and a pipeconnection between the supply tank and the heat exchanger adapted, whenthe circulating means is inoperative as a result of the valve beingopen, to circulate water from the supply tank through the heat exchangerand thence through the drain pipe and upon closing of said valve, tofill the circulating means with water from the supply tank.

10. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of water andhaving means for cooling the water therein, a hollow heat exchangerpositioned beneath the level of the tank bottom and adapted to have aircirculated past it, means for circulating water from the tank throughthe heat exchanger and back to the tank, including a jacket leading fromthe top of the tank and connected to the bottom of the heat exchanger,and a return pipe between the top of said heat exchanger and the tank, avalve controlled drain pipe leading from the top of the heat exchangerand adapted when the valve thereof is opened, to drain the jacket of anywater therein and thus render the circulating with for continuouslymaintaining it full of tap water, and a pipe extending between thesupply tank and the bottom of the heat exchanger adapted, when thecirculating means is inoperative as a result of the valve being open, tocirculate water from the supply tank through the heat exchanger andthence through the drain pipe and upon closing of said valve, to fillthe jacket of the circulating means with water from the supply tank.

11. In an air conditioning apparatus of the character described, thecombination of a cooling tank adapted to contain a column of Water, amechanical refrigerator unit for cooling the water in the tank,including a water cooled condenser and in addition an evaporator in thetank, a hollow heat exchanger disposed beneath the cooling tank andadapted to have air circulated past it, a system for circulating waterfrom the cooling tank through the heat exchanger and thence back to thetank, a valve controlled drain adapted when the valve thereof is opened,to drain said system and render the latter ineffective, a supply tankpositioned adjacent the cooling tank and having means associatedtherewith for continuously maintaining it full of tap water, a pipeextending between the supply tank and the heat exchanger and adapted,when the valve of the drain pipe is opened, to circulate water from thesupply tank through the heat exchanger and then into said drain pipe andwhen the valve is closed, to fill the system with water from said supplytank, and means for supplying Water from said supply tank to thecondenser of the refrigerator unit.

12. In an air conditioning apparatus of the character described, thecombination of a supporting structure, a tank on the supportingstructure adapted to contain a column of water and having means forcooling the Water therein, means on the structure forming an open endedduct adjacent the tank, a heat exchanger in said duct, means forcirculating Water from the tank through the heat exchanger and back tothe tank, means for draining the circulating means when the latter isnot in use, a motor driven fan adjacent the heat exchanger and adaptedwhen driven to circulate air through the duct and past the heatexchanger for cooling purposes, and means including a make-up water tankin the discharge end of said duct for filling the circulating means withWater after draining of said circulating means preparatory to furtheruse of the latter.

FRANK CAIN.

